Small-angle neutron scattering instrumentation

Small angle neutron scattering instruments are specifically designed to examine disordered materials, such as to determine hydration structures during hydrate formation (Koh et al., 2000 Buchanan et al., 2005 Thompson et al., 2006), or to study kinetic inhibitor adsorption onto a hydrate surface (Hutter et al., 2000 King et al., 2000). 

Now spin echo methods are used for a small angle neutron scattering instrument and a triple axis spectrometer to increase the momentum- and energy transfer sensitivities. However, these instruments are not typical because they require novel techniques. 

This research was supported by the Intramural Research Program of the NICHD, NIH. The authors acknowledge the support of the National Institute of Standards and Technology, U.S. Department of Commerce for providing access to the NG3 small angle neutron scattering instrument used in this experiment. This work utilized facilities supported in part by the National Science Foundation under Agreement No. DMR-0454672. 

Abstract In this chapter we discuss practical techniques and instrumentation used in experimental measurements of kinetic and equilibrium isotope effects. After describing methods to determine IE s on rate constants, brief treatments of mass spectrometry and isotope ratio mass spectrometry, NMR measurements of isotope effects, the use of radio-isotopes, techniques to determine vapor pressure and other equilibrium IE s, and IE s in small angle neutron scattering are presented. 

Small-Angle Neutron Scattering. Measurements were made as described previously (10, II) using a multidetector instrument installed in the PLUTO reactor at Harwell and also with the Dll instrument at the Institut Laue-Langevin, Grenoble, France. 

In addition, special capacitor cell structures are designed to meet the requirements of some instrumental measurements (especially in situ techniques) for electrolytes. Here, we describe three types of cells used for in situ Raman, nuclear magnetic resonance (NMR), and small-angle neutron scattering (SANS) characterizations. 

Figure 3.9 Schematic diagram of the 10-m small-angle neutron scattering faciiity at Oak Ridge, TN. The neutron beam used by the instrument is transported from the beam room to the SANS facility level by Bragg reflection from pyrolitic graphite crystals scattering at 90°. Courtesy of Dr. G. D. Wignall.

Results obtained by very-small-angle neutron scattering (V-SANS) performed with the KWS-3 instrument at the FRM 11 research reactor in Garching/Munich on some of the samples of the SDS/CA/water system are shown in Fig. 9. The observed Q dependence is consistent with vesicular structures which have a bilayer thickness much smaller than the radius of the D20-lilled core. In this case the scattering of the shells becomes identical to the scattering of extended lamellar sheets [32]. 

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